What is meant by the heart is the dominical subtle faculty - not the piece of flesh shaped like a pine-cone - the emotions of which are manifested in the conscience and the thoughts of which are reflected in the mind. The term heart indicates that the dominical subtle faculty is to man's spiritual dimensions what the cone-shaped piece of flesh is to the body. For just as the physical heart is a life-machine that pumps the water of life to all the parts of the body, and if it is obstructed or ceases from activity, [life departs and] the body stiffens; so the subtle inner faculty dispenses the light of true life to all the parts of the corpus composed of man's spiritual aspects, and his [mental] states, and hopes. And if, God forbid, the light of belief fades away, his being, with which he contends with the universe, becomes like a motionless spectre, dark in its entirety.

"And on their hearing (wa 'alâ sam'ilim):" the repetition of "on ('alâ)" indicates that the evidences of each [faculty] are independent. For the heart [points to Allâh] with the evidences of the intellect and conscience, and the hearing [points to Him] with evidences from the Qur'an and Hadith (naqlî) and from the outside world. Its repetition also hints that the sealing up of the hearing is not of the same kind as the sealing up of the heart.

Moreover, the singular case of "hearing" despite having a plural on either side of it [that is, the heart and the eyes] is an instance of conciseness, and also contains several signs: it hints that as a verbal noun, [the act of] hearing (sam') [is performed with the ear, which] has no cover [like an eyelid]; and that the one making hear (musmi') is singular; and that what is heard (masmû) by each person is singular; and that a person hears one thing at a time. And it hints at the partnership of all who hear, as though their ears are united becoming one; and at the union of the community and its personification, which makes one imagine that its faculty of hearing is singular; and that one person hearing something suffices the community. It was on account of these points that eloquence required "hearing" to be in the singular. However, the things pertaining to the heart and eyes are different, and their ways are diverse, and their evidences differ, and they receive instruction from different things, and the things that prompt them are various. For these reasons the singular intervenes between two plurals. The heart is followed by the hearing because the hearing forms the heart's character [that is, mostly information reaches the heart through the channel of the ear], and it is closer to it. Also, the hearing resembles the heart in that it receives information from the six directions, [from all sides, while the eyes only look to the front].